[Tkinter] Database with gui

[mark9]

Hello all, I am learning python language. I am trying this exercise I found on web in a course, and I would to improve it. This program shows a window where the user can insert data about his routine and then view data he is searching for.
Problem 1. The search function seems not working well
Problem 2. When selecting one of text entries, I got a "tuple index out of range" error in the console (non affecting funcionality maybe)

I also would like add the option to update some items, instead of adding new ones.
If you find some othere possible improvements I would appreciate.
Thanks for help in advance

Frontend:

from tkinter import *
import backend

def get_selected_row(event):
    global selected_row
    index = list.curselection()[0]
    selected_row = list.get(index)
    e1.delete(0,END)
    e1.insert(END,selected_row[1])
    e2.delete(0,END)
    e2.insert(END,selected_row[2])
    e3.delete(0,END)
    e3.insert(END,selected_row[3])
    e4.delete(0,END)
    e4.insert(END,selected_row[4])
    e5.delete(0,END)
    e5.insert(END,selected_row[5])
    e6.delete(0,END)
    e6.insert(END,selected_row[6])

def delete_command():
    backend.delete(selected_row[0])
    view_command()

def view_command():
    list.delete(0,END)
    for row in backend.view():
        list.insert(END,row)

def search_command():
    list.delete(0,END)
    for row in backend.search(date_text.get(),earning_text.get(),exercise_text.get(),study_text.get(),diet_text.get(),python_text.get()):
        list.insert(END,row)

def add_command():
    backend.insert(date_text.get(),earning_text.get(),exercise_text.get(),study_text.get(),diet_text.get(),python_text.get())

    list.delete(0,END)
    list.insert(END,(date_text.get(),earning_text.get(),exercise_text.get(),study_text.get(),diet_text.get(),python_text.get()))

    view_command()

win = Tk()

win.wm_title('MY ROUTINE DATABASE')

l1 = Label(win, text='Date')
l1.grid(row=0,column=0)
l2 = Label(win, text='Earnings')
l2.grid(row=0,column=2)
l3 = Label(win, text='Exercise')
l3.grid(row=1,column=0)
l4 = Label(win, text='Study')
l4.grid(row=1,column=2)
l5 = Label(win, text='Diet')
l5.grid(row=2,column=0)
l6 = Label(win, text='Python')
l6.grid(row=2,column=2)

date_text = StringVar()
e1 = Entry(win, textvariable=date_text)
e1.grid(row=0,column=1)

earning_text = StringVar()
e2 = Entry(win, textvariable=earning_text)
e2.grid(row=0,column=3)

exercise_text = StringVar()
e3 = Entry(win, textvariable=exercise_text)
e3.grid(row=1,column=1)

study_text = StringVar()
e4 = Entry(win, textvariable=study_text)
e4.grid(row=1,column=3)

diet_text = StringVar()
e5 = Entry(win, textvariable=diet_text)
e5.grid(row=2,column=1)

python_text = StringVar()
e6 = Entry(win, textvariable=python_text)
e6.grid(row=2,column=3)

list = Listbox(win,height=8,width=35)
list.grid(row=3,column=0,rowspan=9,columnspan=2)

sb = Scrollbar(win)
sb.grid(row=3,column=2,rowspan=9)

list.bind('<<ListboxSelect>>',get_selected_row)

b1 = Button(win,text='ADD',width=12,pady=5,command=add_command)
b1.grid(row=3,column=3)

b2 = Button(win,text='Search',width=12,pady=5,command=search_command)
b2.grid(row=4,column=3)

b3 = Button(win,text='Delete date',width=12,pady=5,command=delete_command)
b3.grid(row=5,column=3)

b4 = Button(win,text='View all',width=12,pady=5,command=view_command)
b4.grid(row=6,column=3)

b5 = Button(win,text='Close',width=12,pady=5,command = win.destroy)
b5.grid(row=7,column=3)

win.mainloop()

Backend:

import sqlite3

def connect():
    conn = sqlite3.connect('routine.db')
    cur = conn.cursor()
    cur.execute("CREATE TABLE IF NOT EXISTS routine (Id INTEGER PRIMARY KEY , date text , earnings integer , exercise text , study text , diet text ,python text)")
    conn.commit()
    conn.close()

def insert(date , earnings , exercise , study , diet , python):
    conn = sqlite3.connect('routine.db')
    cur = conn.cursor()
    cur.execute("INSERT INTO routine VALUES (NULL , ?,?,?,?,?,?)" , (date , earnings , exercise , study , diet , python))
    conn.commit()
    conn.close()

def view():
    conn = sqlite3.connect('routine.db')
    cur = conn.cursor()
    cur.execute("SELECT * FROM routine")
    rows = cur.fetchall()
    conn.commit()
    conn.close()
    return rows

def delete(id):
    conn = sqlite3.connect('routine.db')
    cur = conn.cursor()
    cur.execute("DELETE FROM routine WHERE id=? ", (id,))
    conn.commit()
    conn.close()

def search(date='' , earnings='' , exercise='' , study='' , diet='' , python=''):
    conn = sqlite3.connect('routine.db')
    cur = conn.cursor()
    cur.execute("SELECT * FROM routine WHERE date=?  OR earnings=? OR exercise=? OR study=? OR diet=? OR python=?" , (date , earnings , exercise , study , diet , python))
    rows = cur.fetchall()
    conn.commit()
    conn.close()
    return rows

connect()